In my earlier copending application Ser. No. 257,165, filed May 26, 1972 and entitled "Modular Circuit Interrupting Device", a high voltage interrupter was disclosed which included a flexible insulating diaphragm to insulate the manual actuator from the live voltage of the interrupter. In my U.S. Pat. No. 3,755,714, issued on Aug. 28, 1973 and entitled "A Fault Locating and Isolating System for an Electric Power Distribution System", a completely enclosed circuit breaker having the trip mechanism within the circuit breaker and at line voltage is disclosed.